Multiple Images

Objectives

• Describe how light rays can change direction.

• Demonstrate how visible light is reflected.

Materials

• Per student:
  2 mirrors
  Multiple images handout

Key Questions

• Can you find a relationship between the angle of the mirrors and the number of images produced?
• What happens if you place the mirrors facing each other (parallel) with the happy face in between them? (This creates an endless or infinite reflection.)

What To Do

1. Colour the happy face on the Multiple Images handout so that it’s easy to see. The happy face is the object you will be copying.
2. Place the two mirrors facing you, along the lines marked “left mirror” and “right mirror.” The two mirrors should touch at the cross marked “centre” and the right side of the right-hand mirror should be touching point A. Start recording here.
3. Look into the mirrors. Beside point A in the table, record the number of images of happy faces you see (including the one drawn on the page.)
4. Move the right mirror so that it lies along an imaginary line between the centre point and point B. Now, how many happy faces do you see? Record it in the table beside point B.
5. Repeat your observations, moving the right mirror to points C, D, E, F, and G, and taking note of how many faces you see at each angle. What do you notice?

Extensions

• Draw a 10 cm line on a piece of paper. Put part of the line inside the mirror “book” instead of the happy face. Can you make a square? A pentagon? An octagon?
• What angle are the mirrors at to make each shape?